The action star appeared at Comic-Con Friday to help unveil footage from the new “Riddick” film.

Diesel says the roleplaying game Dungeons & Dragons was a “training ground for imagination” and helped him embrace the mythology of Riddick’s world. But becoming a father made him see Riddick’s dark side in a new way.

“What’s inside Riddick is so scary that now that I have kids, when I watch the Riddick character, there’ s a part of me that feels guilty for having such a darkness in that character,” he said. “I look at what he’s doing and I go, ‘That isn’t cool, you shouldn’t have killed that guy.’ It’s only because I have kids now.”

Diesel also hinted at a future in the Marvel universe when responding to a fan question, saying only, “There’s some very big news coming at the end of the month.”